Evidence for a possible anatomical subsite–mediated effect of tobacco in oral potentially malignant disorders and carcinoma

J Oral Pathol Med (2011) 40 : 214–217 Purpose: To test the hypothesis that cigarette smokers develop oral potentially malignant disorders or carcinomas in preferential anatomical subsites. Methods: The association of smoking habit with the presence of oral lesions in specific anatomical subsites was assessed in 123 patients using the odds ratio analysis. Results: When compared to all the other subsites, the relative frequency of smokers with lesions was higher in the buccal mucosa and in the floor of the mouth (FOM) (P = 0.002 and P = 0.005), while it was lower in the tongue (P < 0.0005). Smokers were about 7 years younger than non‐smokers (P = 0.008). Conclusions: The association of smoking and age suggests that smoking may contribute to generate a field of injury that leads to lesions in shorter periods than other causes. The stronger relationship of smoking with lesions in the buccal mucosa and FOM than in the tongue suggests that tissue characteristics mediate the effects of tobacco.     

Changes in the localization of colorectal cancer: Implications for clinical practice

A hospital-based study was performed in order to examine the subsite distribution of colorectal cancer diagnosed in 1992–93 in the Zaanstreek region. The localization was compared with tumours diagnosed in the years 1972–73 and 1982–83. The number of colorectal cancers has markedly increased, and a significant rise in localization of tumours proximal to the splenic flexure has occurred (32% in 1972–73 to 43% in 1992–93). There also appears to be greater incidence of colorectal cancer in women. A trend towards an increase of proximal localization of tumours in women was noted. Possible explanations for this phenomenon are discussed. The results of this study suggest the importance of improved diagnostic accuracy in colorectal cancer and, in addition, may have consequences for screening programmes.     

Three different subsite classification systems for carcinomas in the proximity of the GEJ,but is it all one disease?

BACKGROUND AND AIM: Currently there are three different subsite classification systems for carcinomas in the region of the gastroesophaeal junction (GEJ), namely ICD-O, Munich and Liverpool. The aim of the present study was to compare clinicoepidemiological, pathological and molecular features of adenocarcinomas in the proximity of the GEJ, classified according to their position with respect to the GEJ initially, and then classified according to ICD-O, Munich and Liverpool classifications. METHODS: Forty-seven adenocarcinomas in the proximity of the GEJ were subdivided into groups 1 (exclusively within esophagus), 2 (mainly within esophagus but extending distally across GEJ), 3 (equally present in esophagus and stomach) or 4 (mainly in stomach but extending proximally across GEJ), and analysis of their clinicoepidemiological, pathological and molecular features was performed. Molecular characterization included loss of heterozygosity (LOH) and microsatellite instability analyses. RESULTS: Group 3 carcinomas were younger than other carcinomas in the proximity of the GEJ, but otherwise these carcinomas were similar in their clinicoepidemiological, pathological and molecular features. There were no significant differences between esophageal (groups 1 and 2) and gastric (groups 3 and 4) carcinomas as classified by ICD-O. Munich types I (groups 1 and 2), II (group 3) and III (group 4) carcinomas of the GEJ were also similar. LOH at the site of the Rb tumor suppressor gene and at 17p11.1-p12 was more common in GEJ (groups 2, 3 and 4) than lower third (group 1) esophageal carcinomas classified according to the Liverpool system. CONCLUSION: Overall, adenocarcinomas of the lower esophagus and adenocarcinomas involving the GEJ have similar clinicoepidemiological, pathological and molecular features no matter which subsite classification is used, adding further evidence that they represent the same disease.     

Anatomical subsite discrepancy in relation to the impact of the consumption of alcohol, tobacco and betel quid on esophageal cancer

The carcinogenetic impact of risk factors on esophageal cancer (EC) may differ according to the portion of the esophagus where the tumor occurs. It is unclear why more esophageal squamous cell carcinomas (SCC) developed in the middle location. We carried out a multicenter case-control study in Taiwan to assess anatomical subsite risk discrepancy for this neoplasm in regard to the consumption of alcohol, tobacco and betel quid. Four hundred forty seven incident patients with pathology-proven SCC of the esophagus (107 were upper-third [U/3-EC], 199 middle-third [M/3-EC] and 141 lower-third [L/3-EC] cases), as well as 1,022 gender, age and study hospital matched controls were analyzed by unordered polytomous logistic regression. All consumption of the three substances was related to the development of each subsite of EC, with a heterogeneously higher risk for current smokers (adjusted odds ratio (AOR) = 6.2) found in M/3-EC and for current chewers, in U/3-EC (AOR = 4.9). The joint risk of contracting lower two-third EC for drinking and smoking appeared to significantly surpass those estimated by a multiplicative interaction model. Concomitant exposure to these two agents brought the risks of EC at all three subsites up to 10- to 23.9-fold and additional tobacco-free betel quid to a 30.3- to 75.0-fold. In conclusion, tumor subsite discrepancy risk is related to prolonged exposure to tobacco and betel quid with inflorescence. Alcohol interacts with tobacco in a stronger supra-multiplicative way in the middle portion of the esophagus, probably explaining why esophageal SCC occurs more commonly at this anatomical location.     

Influence of anatomical subsite on the incidence of microsatellite instability,and KRAS and BRAF mutation rates in patients with colon carcinoma

There is a growing amount of data supporting the concept that cancers originating from the proximal and distal colon are distinct clinicopathological entities. The incidence of MSI and BRAF mutation is strongly associated with right sided tumor location, whereas there are conflicting results for KRAS mutation rates. However, to date, no data exist whether and to what extent defined colonic subsites influence MSI status, KRAS and BRAF mutation rates.     

Subsite-specific risk factors for colorectal cancer: a hospital-based case-control study in Japan

To investigate the subsite-specific risk factors for colorectal cancer, we conducted a case-control study, using a common questionnaire which inquired about general lifestyles over the past five years (1988–92), at the Aichi Cancer Center Hospital, Nagoya, Japan. This study compared 432 patients with histopathologically diagnosed colorectal cancer (94 proximal colon [cecum, ascending colon, transverse colon]; 137 distal colon [descending colon, sigmoid colon]; 201 rectum [rectosigmoid, rectum]); and 31,782 first-visit outpatient controls who were free from cancer. In both genders, habitual smoking selectively increased the risk for rectum cancer. Soft or loose feces increased the risk for all subsites of colorectal cancer, particularly in female cancer (odds ratio [OR]=4.5). Among female dietary habits, Japanese-style foods decreased the risk factors for distal colon cancer, but increased the risk for proximal colon cancer. These results suggested that the risk factors for colorectal cancer differ by subsite among such a low-risk population as the Japanese. It is suggested also that irritable bowel (soft or loose feces) might be associated with distal subsites of colorectal cancer, independently or combined with habitual smoking. Cancer Causes and Control 1995, 6, 14–22.Drs Inoue and Tajima, Ms Hirose, and Drs Hamajima and Takezaki are with the Division of Epidemiology, Aichi Cancer Center Research Institute, Nagoya, Japan. Authors are also affiliated with the Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Nagoya, Japan (Drs Hirai and Kato), and the Department of Preventive Medicine, Nagoya University School of Medicine, Nagoya, Japan (Drs Inoue and Ohno). Address correspondence to Dr Inoue, Division of Epidemiology, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya, Japan, 464. This study was funded in part by a Grant-in-Aid for Cancer Research (4-2) and the Comprehensive 10-year Strategy for Cancer Control from the Ministry of Health and Welfare, Japan.     

Smoking, alcohol and gastric cancer risk in Korean men: the National Health Insurance Corporation Study

We investigated the risk of gastric cancer by subsite in relation to cigarette smoking and alcohol in a large population-based cohort of 669 570 Korean men in an insurance plan followed for an average 6.5 years, yielding 3452 new cases of gastric cancer, of which 127 were cardia and upper-third gastric cancer, 2409 were distal gastric cancer and 1007 were unclassified. A moderate association was found between smoking, cardia and upper-third (adjusted relative risk (aRR) 2.2; 95% confidence interval (CI) 1.4-3.5) and distal cancers (aRR=1.4; 95% CI=1.3-1.6). We also found a positive association between alcohol consumption and distal (aRR=1.3; 95% CI=1.2-1.5) and total (aRR=1.2; 95% CI=1.1-1.4) gastric cancer. Combined exposure to high levels of tobacco and alcohol increased the risk estimates further; cardia and upper-third gastric cancers were more strongly related to smoking status than distal gastric cancer.British Journal of Cancer (2007) 97, 700-704. doi:10.1038/sj.bjc.6603893 www.bjcancer.com Published online 17 July 2007.     

Trends in colorectal cancer incidence in Norway 1962–2006: an interpretation of the temporal patterns by anatomic subsite

There have been rapid increases in the incidence of colorectal cancer in Norway since the 1960s, and rates rank among the highest worldwide. The primary objectives are to describe trends in left‐ and right‐sided colon cancer and rectal cancer by calendar period and birth cohort and to generate hypotheses as to the etiological factors in operation. Although the age‐adjusted incidence rates of both colon and rectal cancer increased in Norway in both sexes up to the 1980s, subsite‐ and age‐specific analyses reveal a deceleration in the rate of increase thereafter, apparent in the rates of both left‐sided colon and rectal cancer. Overall trends in incidence of right‐sided colon cancer continue to increase in both sexes. Rates in both left‐ and right‐sided colon cancers have tended to stabilize or decrease among successive generations born after 1950, however, while incidence rates of rectal cancer appear to be increasing in recent generations. The all‐ages rates are thus in keeping with the commonly reported “left to right shift” of colon cancer, although standardization masks important observations. The cohort patterns provide further evidence that factors earlier in life are important, and while the complex etiology makes interpretation difficult, modifications in diet, obesity and physical activity in Norway are likely among the drivers of the trends in one or more of the colorectal subsites examined. In summary, the recent downturn in the disease at younger ages provides some reason for optimism, although possible increases in rectal cancer among recent birth cohorts are of concern.     

Cigarette smoking and the risk of gastric cancer: a pooled analysis of two prospective studies in Japan

To examine the association between cigarette smoking and the risk of gastric cancer, we conducted a pooled analysis of 2 population-based prospective cohort studies in rural northern Japan. Cohort 1 included 9,980 men (>or=40 years old) and Cohort 2 included 19,412 men (40-64 years old). The subjects completed a self-administered questionnaire on cigarette smoking and other health habits. We identified 228 cases of gastric cancer among Cohort 1 subjects (9 years of follow-up with 74,073 person-years) and 223 among Cohort 2 subjects (7 years of follow-up with 141,675 person-years). From each cohort, we computed the relative risk (RR) and 95% confidence interval (CI) of gastric cancer associated with smoking using a Cox regression analysis and pooled these estimates to obtain summary measures. The pooled multivariate RRs (95% CIs) for current smokers and past smokers compared to subjects who had never smoked were 1.84 (1.39-2.43) and 1.77 (1.29-2.43), respectively. The higher number of cigarettes smoked per day among current smokers was associated with a linear increase in risk (trend p < 0.05). The significant increase in risk for past smokers remained for up to 14 years after cessation. An increased risk was noted for cancer of the antrum but not for cardia or body lesions. The risk was increased for both differentiated and nondifferentiated histologic subtypes. Our findings support the hypothesis that cigarette smoking is a risk factor for gastric cancer.